This invention generally relates a system for providing on-board timing of a vehicle traversing a predetermined course. The invention is more particularly directed to an on-board timing device for a race car to indicate the time elapsed between predetermined markers by the race car in response to signals generated when the race car passes a reference marker on or adjacent to the track.
During an automobile race it is important that the driver be instantaneously provided with the time that was required to finish the distance or lap that he has just completed. Typically such timing information is provided by a team member in the pit actuating a hand held stop watch which is manually actuated and manually deactivated as the race car completes the lap. The timing information is then radioed from the pit to the headphone worn by the driver to provide him with the lap timing information. Obviously,the results of such timing procedures are not accurate. The actuating and deactivating of the stop watch and in passing the information on to the driver produces errors.
Some race tracks utilize electronic timers which are triggered by the breaking of a electromagnetic beam which is directed across the track. However, in order to be useful to a driver during a race when many cars break the beam intermittently or continuously, a monitor (typically, a team member) is required to monitor when a specific car breaks the beam and to pass the time information on to the driver through the headphones.
One timing system, disclosed in U.S. Pat. No. 4,857,886 uses a stationary transceiver located at selected locations along the course. A mobile transmitter is located on each vehicle for transmitting a distinctive coded transmission of short time duration. A network controller must be located in the vicinity of the course for receiving transmissions from the transmitting portion of each transceiver.
Another type of timing system is disclosed in U.S. Pat. No. 4,392,122 in which a racing car is equipped with a magneic sensing coil for producing electrical signals in response to detection of magnets disposed in one or more positions along the course. The output of the sensing coil is used to control on-board timing circuitry to enable the average vehicle speed over the course to be determined and displayed. The system requires (for race cars) two timers and two displays which are operated alternately so that at the end of each lap the signal produced by the sensor is used to start one timer and stop the other timer which will have started at the beginning of the lap. A discriminator is required to control alternate operation of the two timers and display units. Applicant uses a single timer and display along with a presettable countdown timer gate circuit,thus reducing component and system parts cost and also reduces the size and weight of the system while making it easier for the driver to interpret. Without this presettable countdown timer gate circuit the use of an on-board timing system in the racing vehicle is not practical because extraneous markers and other objects on or along the racing track will falsely trigger the timing sequence.
In applicant's system, the single clock is actuated at the start of the lap but delays an indication of useful timing information until the race car has completed the first lap and passed finish line, at which instance the lap time is displayed and the timing of the next lap is initiated and progresses but is not displayed until the finish line is again crossed.